Method of and apparatus for refrigeration



Marci. 6, 1929. s, R 1,706,621

METHOD OF AND APPARATUS FOR REFRIGERATION Filed Nov.26, 1926 5 Sheets-Sheet l INVENTOR:

BY W.

ATTORNEY March 26, 1929. A. s. LIMPERT METHOD OF AND APPARATUS FOR REFRIGERATION Filed Nov. 26, 1926 3 Sheets-Sheet 2 INVENTOR.

7 1M QM i 44 ATTORNEY March 26, 1929. A. s. LIMPERT METHOD OF AND APPARATUS FOR REFRIGERATION Filed Nov. 26. 1926 3 Sheets-Sheet 3 "T 7 22 m I r" ZLJIJ 1 INVENTOR.

i QATTORNEY Patented Mar. 26, 1929.

UNITED STATES ALEXANDER s. LIMPERT, 01? DAY SHORE, NEW YORK.

METHOD OF AND APPARATUS FOR REFRIGERATION.

App ication filed November 26, 1926. Seria No. 150,796

This invention relates to a cooling unit or expansion chamber of refrigerating machines or systems and has for its particular objects the production of a cooling unit which is extremely compact, cheap to manufacture,

highly durable and unusually efficient.

Heretofore it has been common practice to employ brine tanks in the coolingunits of many refrigerating machines in order that the same would serve as efficient chilling reservoirs, 'thus serving to maintain a uniform temperature in a food compartment of a refrigerator. In those cases where the brine tank has been dispensed with there was a consequent lack of chilling capactiy, as this function of the brine reservoir might be aptly termed, and consequently the machines under the control of an automatic thermostat would be in operation far more frequently than would be the case were a chilling reser voir, such as a brine tank, employed.

My investigations have led to the discovery of a novel form of reservoir which is far less cumbersome and objectionable than a brine tank, which possesses even greater chilling capacity than a brine tank of anywhere near the same dimensions and which, because of its high chilling capacity, is admirably adapted for the production of ice cubes and for the efiicient maintenance of any desired temperature in the food chamber of the refrigerator, because of its unusual responsiveness to the temperature of the refrigerator coil embedded therein, all of which is hereinafter set forth in detail.

In the accompanying drawings, in which I have illustrated a preferred embodiment of like.

my invention,

Figure 1 designates a perspective view, partially in section, of my lmproved cooling unit for an ice box which is adapted to be re frigerated by means of an electrical refrigerating machine, by brine circulation or other means for vaporizing and condensing a refrigerant medium; v

Fig. 2 is a plan view; Fig. 3 a vertical transverse section on the line 3-3 of Fig. 2, and

Fig. 4 is a longitudinal vertical section on the line 44 of Fig. 3; Fig. 5 is a front elevation;

' Fig. 6 is a plan View and Fig. 7 a rear elevation of a modification showing a sectional form f cooling unit which may be extended at will, and

Fig. 8 is a vertical transverse section through the section next to the top, taken on the line 8-8.

Referring to the drawings and the construction shown therein, the reference numeral 1 designates a block formed by suitably coring a casting to provide three small chamembedded, as shown in thedrawings, only in the side walls with an interconnecting straight section, but the construction as herein illustrated is ample for ordinary domestic refrigeration purposes.

A thermostat receptacle or well 8 is adapted to receive the thermostat which serves to control the operation of the motor of the compressor unit (not shown) and as is evident the ends a, a of coil 7 are adapted to be in com-- munication with the higlrand low side respectively of the compressor.

The slab-like walls of the block 1 are provided with slots 9 formed between the respective pairs of lugs 10 cast thereon and these slots serve to receive and retain radiating fins 11 which preferably are snugly fitted therein and effectively held by upsetting the metal of the lugs with a prick punch or the In the modification shown in Figs. 5 to 8 inclusive, the cooling element is built to any desired size by assembling a series of units each carrying its own cooling coil embedded in the cross partitions thereof. In this construction the coil 20 is cast in the'partitions 21, 21 or 21"-in the manner previously described with respect to the constructior'r shown in Figs. 1 to 4 inclusive and as shown, the coil of each section has a funnel member 22 at one end and a. spout or nozzle member 23 at its opposite end which are adapted to be fitted to the dissimilar members of an adjacent section and the joint therebetween wiped with molten metal in the usual manner to securely seal the same. As will be observed, the alternate sections jare similar in so far as the arrangement of the coil and its terminals is concerned, whereas the alternate sections k are likewise similar to each other, but the lower section Z is slightly different, the same being provided with a thermostatic well 24 and having a second funnel member 22 at the lefthand rear'corner, viewing the same from the front, and which funnel is adapted to receive and be tightly connected s to a refrigerant return pipe 25, which .extends through apertures 26, provided in each of the sections. Locking nuts '27 or the like serve to seal the joint between said. pipe and the walls of the aperturgs'26, besides centering saidpipe therein.

Preferably in the construction of the block 1 I utilize an alloy commonly used as casting metal composed of about 97% of zinc and 3% of a mixture of aluminum and copper which melts several hundred degrees below the melting point of the copper which is utilized in the coil embedded in such metal, although in lieu of such casing metal Babbitt metal, aluminum or other suitable metal havkind to produce a unit of the desired capacity,

namely, one top section and one or more sections corresponding to sections j and one or more sections corresponding to sections k. These units when assembled, so that their flanges 28 are in alignment on stay-bolts 29 carrying collars 30, 30', are securely locked together by means of nuts 31. Vanes 11 may also be mounted as above described in connection with Figs. 1 to 4 inclusive in the slots 9 formed between pairs of lugs 10 which may be provided on each castingas indicated in Fig. 6. I

The drawers 32, 33, are inserted in the chambers 34, 35 respectively, and these drawers may be either adapted for freezing small .cubes of ice or for large cakes of ice or pre-- serving food stuffs, is desired.

My improved cooling unit has an extremely "large capacity which consequently results in minimizing the number of operations requlred of the compressor. It is extremely compact, it is highly responsive to and closely v approximates the temperature of the coil embedded in the partitions thereof and con- 'sequently it is possible to maintain any desired temperaturewith-a mlnlmum expendlture of power and a minimum cost.

The extent ofthe radiating surfaces can i be readily adjusted as desired and, likewise,-

the capacity of the unit when made in the sectional form as described can be indefinitely increased. Also because of the very thin tub- My improved cooling unit, as herein described, is not only highly efficient, as above stated, because of thefd'irect conduction so that the temperature of the cooling medium is transmitted by direct conduction through the coil ando the slab in which it is embedded to the chamber to be refrigerated, the same also is adapted to eflect the automatic return of the lubricating oil which becomes entrained with the refrigerant and tends to collect in the bottom of the cooling unit for the reason that unlike cooling units wherein there is a brine or refrigerating chamber as distinguished from'a coil, the refrigerant in my cooling unit will collect in the lowest point of the until until a liquid seal is effected, whereupon, as the suction of the low side of the compressor builds up, the refrigerant will he suddenly sucked or puked through the coil and to the suction side of the pump, thus clearing the coil temporm rily, whereas this action is impossible with machines wherein relatively large chambers for liquid refrigerant are provided. The copper or like metal coil, although extremely thin and therefore capable of imparting the temperature of the refrigerant fluid therein to the surrounding metal, is nevertheless so reinforced by the casting in which it is embedded that not only will any pores be automatically sealed or reinforced, but there is no tendency for the same to bulge or break down because of the pressure employed in the refrigerating machine, whether the same be 50 lbs. or 200.'lbs. As a consequence, it is not necessary to employ an ex pensive thin walled C011 whichdias been subjected to exhaustive'tests to determine the strengthand porosity thereof.

Preferably the thermostatic well is provided in the bottom section, as obviously, the thermostat will then not act until the bottom pipe or slab, which will naturally be the last to cool, has reached the desired temperature and thus it will insure that all the sections have reached at least this temperature prior to the operation of thethermostat.

In the solid block construction herein described, the-drawer chambers are, as illustrated, cored in the block, while the coils are embedded in the walls or partitions thereof during the. casting operation and likewise, the grooves for the reception of the radial fins are cast on the outer faces of the blocks, whereby upon the insertion of the radiating fins any desired additional amount of radiation can be obtained without increasing the number of cube drawers which ordinarily otherwise would be required and which, of course, would obviously add to the expense because of necessitating a surplus number of cube trays or drawers.

If desired, a second coil can be embedded in the wall or partition of the block comprising a cooling unit for the purpose of circulating therethrough drinking Water to be be cooled, but this is only feasible where large quantities of water are to be cooled, other- .wise, either the temperature of the cooling unit would have to be maintained too high for practical purposes or the water in the drinking water coils would become frozen because of insuflicient circulation.

While I prefer to cast the metal tube which I employ as the cooling coil in a block of metal which has a lower boiling point because of the facility. with which the same can be accomplished and the relative cheapness of the block of metal, nevertheless, in some case I may cast a pro-formed metal tube, for example, of copper or brass in a block having substantially the same melting point and comprising a metal of the same chemical composition as that from which the tube is formed and in such case either water or oil or other suitable cooling medium is employed to radiate the heat from the tube and prevent melting thereof when the liquid metal is poured into the mold containing said tube or coil, and also the temperature of the liquid metal at the moment of pouring is preferably as low as consistent with the proper pouring thereof in order that the solidification of the metal'will occur as rapidly as possible. However, for many purposes, such a procedure as above described would'be too expensive, although obviously the' conductivity of such a block Would be far superior to that of an alloy, such as zinc alloy herein described.

Various modifications and changes within the scope of the appended claims may be obviously made without departing from the spirit of my invention as herein described.

Having thus described my invention, what I claim and desire to obtain by United States Letters Patent is:

1. A sectional cooling device for refrigerating machines,- comprising a plurality of dissimilar cooling units each having at least one of its walls formed of cast metal and having a pipe of a higher melting point cast integral therewith, a tubular inlet and a tubular outlet member, the respective inlet and outlet members of different units between being adapted to engage respectively the out let and inlet members of adjacent units, and vanes removably attached to said unit.

2. A sectional cooling device for refrigerating machines, comprising a plurality of dissimilar cooling units each having at least one of its walls formed of cast metal and having a pipe of a higher melting point cast integral therewith, and tubular inlet and outlet members, the respective inlet and outlet members of different units between being adapted to engage respectively theoutlet and inlet members of adjacent units.

3. An expansion cooling unit for refrigerating systems, comprising a chambered vessel, one wall of which is of metal and contains embedded therein a preformed tubular member of metal, which tubular member is provided with an inlet for the admission of refrigerant thereto and an outlet for the escape of refrigcrent therefrom and a portion of said embedded member extending to a level substantially below the said outlet thereby forming a temporary lubricant-collecting well.

4.'An expansion cooling unit for refrigerating systems, comprising a chambered vessel of cast metal and containinga pro-formed metal conduit embedded therein by a casting operation, said conduit being composed of a metal of considerably lower melting point than the metal of said vessel and said conduit having an inlet for the admission of refrigerant thereto and an outlet for the escape of refrigerant therefrom and said embedded conduit extending to a level substantially below the said outlet thereby forming a temporary lubricant-collecting well.

5. An expansion cooling unit for refrigerating machines, comprising a metal casting, a tubular core extending through a portion thereof, the wall of metal immediately surrounding the said core being of different physical texture than that of said casting and a portion of said core extending to a level substantially below that of another portion of said core, thereby forming atemporary luln'icant-collecting wellin said castin Signed at New York, in the county and State of New York this 22nd day of November 1926. ALEXANDER S. LIMPERT. 

